Gaming devices (e.g., reeled slot machines or video poker machines) generate more than $15 billion per year in revenue for casinos in the United States alone. This figure accounts for the majority of the gaming revenue for a typical United States casino. The situation is similar in other countries in which gaming devices are popular, such as Europe and Australia. Accordingly, casino operators are interested in increasing the enjoyment of playing a slot machine in order to maintain or increase this level of revenue.
Since casino profits are based on the amount wagered by patrons, casinos are highly motivated to expand and retain share within their given market. Increased playing duration, average wager, and rates of play are factors contributing to the profitability of the slot machines and other gaming devices of a casino.